incubator-nuttx/include/nuttx/module.h

251 lines
8.5 KiB
C

/****************************************************************************
* include/nuttx/module.h
*
* Copyright (C) 2015 Gregory Nutt. All rights reserved.
* Author: Gregory Nutt <gnutt@nuttx.org>
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
*
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in
* the documentation and/or other materials provided with the
* distribution.
* 3. Neither the name NuttX nor the names of its contributors may be
* used to endorse or promote products derived from this software
* without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
* "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
* LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
* FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
* COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
* INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
* BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS
* OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED
* AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN
* ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
* POSSIBILITY OF SUCH DAMAGE.
*
****************************************************************************/
#ifndef __INCLUDE_NUTTX_MODULE_H
#define __INCLUDE_NUTTX_MODULE_H
/****************************************************************************
* Included Files
****************************************************************************/
#include <nuttx/config.h>
#include <sys/types.h>
#include <stdint.h>
#include <stdbool.h>
#include <elf32.h>
#include <nuttx/arch.h>
#include <nuttx/symtab.h>
#include <nuttx/binfmt/binfmt.h>
/****************************************************************************
* Pre-processor Definitions
****************************************************************************/
/* Configuration ************************************************************/
#ifndef CONFIG_MODULE_ALIGN_LOG2
# define CONFIG_MODULE_ALIGN_LOG2 2
#endif
#ifndef CONFIG_MODULE_BUFFERSIZE
# define CONFIG_MODULE_BUFFERSIZE 128
#endif
#ifndef CONFIG_MODULE_BUFFERINCR
# define CONFIG_MODULE_BUFFERINCR 32
#endif
#define MODULENAME_MAX 16
/****************************************************************************
* Public Types
****************************************************************************/
/* This is the type of the function that is called to uninitialize the
* the loaded module. This may mean, for example, un-registering a device
* driver. If the module is successfully initialized, its memory will be
* deallocated.
*
* Input Parameters:
* arg - An opaque argument that was previously returned by the initializer
* function.
*
* Returned Value:
* Zero (OK) on success; a negated errno value on any failure to
* initialize the module. If zero is returned, then the module memory
* will be deallocated. If the module is still in use (for example with
* open driver instances), the uninitialization function should fail with
* -EBUSY
*/
typedef CODE int (*mod_uninitializer_t)(FAR void *arg);
/* A NuttX module is expected to export a function called module_initialize()
* that has the following function prototype. This function should appear as
* the entry point in the ELF module file and will be called bythe binfmt
* logic after the module has been loaded into kernel memory.
*
* Input Parameters:
* uninitializer - The pointer to the uninitialization function. NULL may
* be returned if no uninitialization is needed (i.e, the the module
* memory can be deallocated at any time).
* arg - An argument that will be passed to the uninitialization function.
*
* Returned Value:
* Zero (OK) on success; a negated errno value on any failure to
* initialize the module.
*/
typedef CODE int (*mod_initializer_t)(mod_uninitializer_t *uninitializer,
FAR void **arg);
#ifdef __KERNEL__
/* This is the type of the callback function used by mod_registry_foreach() */
struct module_s;
typedef CODE int (*mod_callback_t)(FAR struct module_s *modp, FAR void *arg);
#endif
/****************************************************************************
* Public Function Prototypes
****************************************************************************/
#undef EXTERN
#if defined(__cplusplus)
#define EXTERN extern "C"
extern "C"
{
#else
#define EXTERN extern
#endif
/****************************************************************************
* Name: mod_getsymtab
*
* Description:
* Get the current kernel symbol table selection as an atomic operation.
*
* Input Parameters:
* symtab - The location to store the symbol table.
* nsymbols - The location to store the number of symbols in the symbol table.
*
* Returned Value:
* None
*
****************************************************************************/
#ifdef __KERNEL__
void mod_getsymtab(FAR const struct symtab_s **symtab, FAR int *nsymbols);
#endif
/****************************************************************************
* Name: mod_setsymtab
*
* Description:
* Select a new kernel symbol table selection as an atomic operation.
*
* Input Parameters:
* symtab - The new symbol table.
* nsymbols - The number of symbols in the symbol table.
*
* Returned Value:
* None
*
****************************************************************************/
#ifdef __KERNEL__
void mod_setsymtab(FAR const struct symtab_s *symtab, int nsymbols);
#endif
/****************************************************************************
* Name: insmod
*
* Description:
* Verify that the file is an ELF module binary and, if so, load the
* module into kernel memory and initialize it for use.
*
* NOTE: mod_setsymtab had to have been called in board-specific OS logic
* prior to calling this function from application logic (perhaps via
* boardctl(BOARDIOC_OS_SYMTAB). Otherwise, insmod will be unable to
* resolve symbols in the OS module.
*
* Input Parameters:
*
* filename - Full path to the module binary to be loaded
* modulename - The name that can be used to refer to the module after
* it has been loaded.
*
* Returned Value:
* Zero (OK) on success. On any failure, -1 (ERROR) is returned the
* errno value is set appropriately.
*
****************************************************************************/
int insmod(FAR const char *filename, FAR const char *modulename);
/****************************************************************************
* Name: rmmod
*
* Description:
* Remove a previously installed module from memory.
*
* Input Parameters:
*
* modulename - The module name. This is the name module name that was
* provided to insmod when the module was loaded.
*
* Returned Value:
* Zero (OK) on success. On any failure, -1 (ERROR) is returned the
* errno value is set appropriately.
*
****************************************************************************/
int rmmod(FAR const char *modulename);
/****************************************************************************
* Name: mod_registry_foreach
*
* Description:
* Visit each module in the registry. This is an internal OS interface and
* not available for use by applications.
*
* Input Parameters:
* callback - This callback function was be called for each entry in the
* registry.
* arg - This opaque argument will be passed to the callback function.
*
* Returned Value:
* This function normally returns zero (OK). If, however, any callback
* function returns a non-zero value, the traversal will be terminated and
* that non-zero value will be returned.
*
* Assumptions:
* The caller does NOT hold the lock on the module registry.
*
****************************************************************************/
#ifdef __KERNEL__
int mod_registry_foreach(mod_callback_t callback, FAR void *arg);
#endif
#undef EXTERN
#if defined(__cplusplus)
}
#endif
#endif /* __INCLUDE_NUTTX_MODULE_H */